This invention relates to a heat exchanger applied to, for example, a vaporizer for a fuel cell system.
Tokkai Hei 9-79694 issued by the Japanese Patent Office in 1997 discloses a heat exchanger provided with a plurality of fuel supply nozzles on a header to uniformly distribute liquid in the heat exchanger.
Tokkai 2000-111244 issued by the Japanese Patent Office in 2000 discloses a heat exchanger provided with a liquid distribution layer made of sintered material or a liquid distribution layer using a serrated fin on the bottom surface of a box type container for the same purpose.
The container is disposed on the top of the main body of the heat exchanger. The liquid distribution layer of the above construction allows liquid in the container to drop uniformly to the main body of the heat exchanger.
The former device requires a large space for mounting nozzles on the header, as a result, the header becomes larger. In the latter device, because a lag time is generated between start and stop of liquid supply to the container, and start and stop of operation of the heat exchanger due to a considerable amount of liquid stored in the liquid distribution layer and in the container, the control response of the heat exchanger is poor.
It is therefore an object of this invention to provide a compact liquid supply mechanism for a heat exchanger which has a good response in liquid supply control.
In order to achieve the above object, this invention provides a heat exchanger comprising a body in which a plurality of heat rendering fluid passages in which heat rendering fluid flows and a plurality of heat receiving fluid passages in which heat receiving fluid flows are formed, a header disposed on the top of the body, and a fuel supply member fitted to a lateral face of the header.
The heat receiving fluid passages have openings directed upward. The header comprises a bottom plate having a plurality of through holes communicating with the openings of the heat receiving fluid passages, and a top plate fixed to the bottom plate. The bottom plate and the top plate partitions a plurality of fluid conducting passages communicating with the through holes and a fluid distribution space communicating with the fluid conducting passages therebetween. The fuel supply member supplies the heat receiving fluid to the fluid distribution space.
The details as well as other features and advantages of this invention are set forth in the remainder of the specification and are shown in the accompanying drawings.